Cosmic perturbations with running G and Lambda - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




Cosmic perturbations with running G and Lambda - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: Cosmologies with running cosmological term Lambda and gravitationalNewton-s coupling G may naturally be expected if the evolution of theuniverse can ultimately be derived from the first principles of Quantum FieldTheory or String Theory. In this paper, we derive the general cosmologicalperturbation equations for models with variable G and Lambda in which thefluctuations in both variables are explicitly included. We demonstrate that, ifmatter is covariantly conserved, the late growth of matter densityperturbations is independent of the wavenumber. Furthermore, if Lambda isnegligible at high redshifts and G varies slowly, we find that thesecosmologies produce a matter power spectrum with the same shape as that of theconcordance LCDM model, thus predicting the same basic features on structureformation. Despite this shape indistinguishability, the free parameters of thevariable G and Lambda models can still be effectively constrained from theobservational bounds on the spectrum amplitude.



Author: Javier Grande, Joan Sola, Julio C. Fabris, Ilya L. Shapiro

Source: https://arxiv.org/







Related documents